Printable View
My Rad fans run all the time as long as the car is turned on.
I unplugged one of them at the fuse box because my engine wont come up to temp and I freeze my ass off in the morning otherwise.
Since I bought my car it has been this way! How do I fix this problem? I want the fans to come on when the engine comes up to temp and turn off otherwise.
The motors are fine....the fuese are fine..no PGM-FI light...ECU shows no Codes!
i'd guess your temp sending unit is hosed?
Could be a few things.
Could be a wire shorted to ground since thats what the switch does when it reaches 189-199 degress.
Best way to check the switch would be to pull it and check for conitnuity across the terminals with it disconnected. If you have contimuity with it cold then its bad.
It may be your cooling fan relay stuck in the closed postition
If neither of those work take a meter if you have one, pull the fuses and start checking the wiring. If I'm thinking right with the key off and both fuses out (20amp and 70 amp under the hood) you should get an open on both wires going into the fan.
I can give you a hand if you need it, just shoot me a PM, if I can fix an airplane off schematics I can fix a cooling fan off them.
all good ideas....100% its a short somewhere!
I need to know where the switch is that turns the fans off and on though....I cant test it if I cant see it!
I own a prelude though...I hope its in the same place!
at least they are stuck on and not off!
The switch in the radiator controls the larger fan, the switch in the thermostat housing controls the smaller fan.
Exactly what I was going to say. You have a unintended ground somewhere and you need to find that. I suggest you get a DMM (Digital Multimeter) if you don't already have one.Quote:
Originally posted by My Cousin Vinny
Could be a few things.
Could be a wire shorted to ground since thats what the switch does when it reaches 189-199 degress.
Best way to check the switch would be to pull it and check for conitnuity across the terminals with it disconnected. If you have contimuity with it cold then its bad.
It may be your cooling fan relay stuck in the closed postition
If neither of those work take a meter if you have one, pull the fuses and start checking the wiring. If I'm thinking right with the key off and both fuses out (20amp and 70 amp under the hood) you should get an open on both wires going into the fan.
I can give you a hand if you need it, just shoot me a PM, if I can fix an airplane off schematics I can fix a cooling fan off them.
-Mike
there are no switches on my rad...and no switches on my thermo housing.
The rad is just the rad...no switches I can see!
The thermo housing has 3 wires going to it. Two in a green plug and one to the resistor that controls and dash thermostat!
Am I missing something?
there should be a switch on the bottom of the radiator
You could just wire a toggle switch on your dash to manually control the fans.
maybe the temp sensor (at the bottom of the rad.) is broken, so the former owner grounded the wire ....(that's what i did on an old prelude :))
I'll check it out...
I'd really like the fans to run 100% the way they should though!
could be a bad sensor in the rad. Nice to see another prelude guy on here. What year and model?
87 prelude SI Black
